Use of the [R] flag causes a HTTP redirect to be issued to the browser. If a fully-qualified URL is specified (that is, including http://servername/) then a redirect will be issued to that location. Otherwise, the current protocol, servername, and port number will be used to generate the URL sent with the redirect.

Any valid HTTP response status code may be specified, using the syntax [R=305], with a 302 status code being used by default if none is specified. The status code specified need not necessarily be a redirect (3xx) status code. However, if a status code is outside the redirect range (300-399) then the substitution string is dropped entirely, and rewriting is stopped as if the L were used.

In addition to response status codes, you may also specify redirect status using their symbolic names: temp (default), permanent, or seeother.

You will almost always want to use [R] in conjunction with [L] (that is, use [R,L]) because on its own, the [R] flag prepends http://thishost[:thisport] to the URI, but then passes this on to the next rule in the ruleset, which can often result in 'Invalid URI in request' warnings.